For the experimental confirmation, clarification of the molecular basis for heterophilic adhesion is important to support the experimental idea. A possible candidate for the heterophilic adhesion molecules are TgrB1 and TgrC1, which is manifested in dicty slug [1]}. Further, the adhesion distribution on the cell membrane exhibits a polarization [2]}. This polarization of these adhesion molecules is the preferred feature for inducing cell Marangoni effect on tissue interfaces. However, the discussed scenario assumes the manifestation of different heterophilic adhesion molecules in the two tissues. In the case of dicty, this corresponds to the situation in which TgrB1(or C1) acts only in the prestalk region of the slug and TgrC1(or B1) acts only in the remaining region (See Fig. REF (a)).
To the best of our knowledge, such separated region-specific action of heterophilic adhesion molecules has not been observed. At the very least, the genes encoding TgrB1 and TgrC1 have a common promoter region and are usually transcribed simultaneously [3]}.
Therefore, the direct confirmation of cell Marangoni flow should need the direct confirmation of the insitu functional adhesion activity of TgrB1 and TgrC1 on cell membrane.
